C/2013 S1 (Catalina)
| Parameter |
Value |
| Designation |
C/2013 S1 (Catalina) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-08-02T22:01:29.435520Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:40Z |
| Obs used |
109 |
| NEO |
- |
| M1 |
13.500 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-10-10.0000000 |
| e |
1.00043244 |
| q (au) |
2.824323 |
| a (au) |
-6531.154578 |
| i (deg) |
83.961966 |
| Ω (om, deg) |
221.536559 |
| ω (w, deg) |
166.064281 |
| M (ma, deg) |
0.000127 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.895 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.895 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-0.503 |
| k |
0.800 |
| δ90 |
10.000 |
| Parameter |
Symbol |
Range |
Description |
| Absolute magnitude at 1 AU from Sun and Earth |
H0 |
-5 to 20 |
Intrinsic brightness of the comet |
| Photometric slope parameter |
n |
2 to 6 |
Rate of brightness change with heliocentric distance |
| Forward scattering asymmetry factor |
gf |
0.8 to 1 |
Degree of forward scattering |
| Backward scattering asymmetry factor |
gb |
-1 to -0.5 |
Degree of backward scattering |
| Partitioning coefficient |
k |
0.8 to 1 |
Ratio between forward/backward scattering contributions |
| Dust-to-gas brightness ratio |
δ90 |
1 to 10 |
Relative contribution of dust scattering to gas emission |
Reference: EPSC-DPS2025-160
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
12:18:28.52 |
-59:50:23.9 |
HIP 60012 |
12.88 |
| 2026-02-03 12:00 |
12:18:24.05 |
-59:50:54.3 |
HIP 60012 |
13.38 |
| 2026-02-04 00:00 |
12:18:19.52 |
-59:51:24.2 |
HIP 60012 |
13.91 |
| 2026-02-04 12:00 |
12:18:14.93 |
-59:51:53.7 |
HIP 60012 |
14.45 |
| 2026-02-05 00:00 |
12:18:10.29 |
-59:52:22.9 |
HIP 60012 |
15.00 |
| 2026-02-05 12:00 |
12:18:05.59 |
-59:52:51.6 |
HIP 60012 |
15.56 |
| 2026-02-06 00:00 |
12:18:00.84 |
-59:53:19.9 |
HIP 60012 |
16.14 |
| 2026-02-06 12:00 |
12:17:56.03 |
-59:53:47.8 |
HIP 60012 |
16.72 |
| 2026-02-07 00:00 |
12:17:51.17 |
-59:54:15.3 |
HIP 60012 |
17.32 |
| 2026-02-07 12:00 |
12:17:46.25 |
-59:54:42.4 |
HIP 60012 |
17.92 |
| 2026-02-08 00:00 |
12:17:41.28 |
-59:55:09.1 |
HIP 60012 |
18.53 |
| 2026-02-08 12:00 |
12:17:36.26 |
-59:55:35.3 |
HIP 60012 |
19.15 |
| 2026-02-09 00:00 |
12:17:31.18 |
-59:56:01.1 |
HIP 60058 |
19.54 |
| 2026-02-09 12:00 |
12:17:26.05 |
-59:56:26.4 |
HIP 60058 |
19.57 |
| 2026-02-10 00:00 |
12:17:20.87 |
-59:56:51.4 |
HIP 60058 |
19.63 |
| 2026-02-10 12:00 |
12:17:15.64 |
-59:57:15.9 |
HIP 60058 |
19.74 |
| 2026-02-11 00:00 |
12:17:10.35 |
-59:57:39.9 |
HIP 60058 |
19.88 |
| 2026-02-11 12:00 |
12:17:05.02 |
-59:58:03.6 |
HIP 60058 |
20.06 |
| 2026-02-12 00:00 |
12:16:59.63 |
-59:58:26.7 |
HIP 60058 |
20.28 |
| 2026-02-12 12:00 |
12:16:54.20 |
-59:58:49.4 |
HIP 60058 |
20.54 |
| 2026-02-13 00:00 |
12:16:48.71 |
-59:59:11.7 |
HIP 60058 |
20.83 |
| 2026-02-13 12:00 |
12:16:43.18 |
-59:59:33.5 |
HIP 60058 |
21.15 |
| 2026-02-14 00:00 |
12:16:37.60 |
-59:59:54.9 |
HIP 60058 |
21.51 |
| 2026-02-14 12:00 |
12:16:31.97 |
-60:00:15.8 |
HIP 60058 |
21.89 |
| 2026-02-15 00:00 |
12:16:26.29 |
-60:00:36.2 |
HIP 60058 |
22.31 |
| 2026-02-15 12:00 |
12:16:20.57 |
-60:00:56.2 |
HIP 59919 |
22.42 |
| 2026-02-16 00:00 |
12:16:14.80 |
-60:01:15.7 |
HIP 59919 |
22.40 |
| 2026-02-16 12:00 |
12:16:08.98 |
-60:01:34.8 |
HIP 59919 |
22.43 |
| 2026-02-17 00:00 |
12:16:03.12 |
-60:01:53.3 |
HIP 59919 |
22.48 |
| 2026-02-17 12:00 |
12:15:57.21 |
-60:02:11.4 |
HIP 59919 |
22.58 |
| 2026-02-18 00:00 |
12:15:51.26 |
-60:02:29.0 |
HIP 59919 |
22.71 |
| 2026-02-18 12:00 |
12:15:45.27 |
-60:02:46.2 |
HIP 59546 |
22.74 |
| 2026-02-19 00:00 |
12:15:39.23 |
-60:03:02.8 |
HIP 59546 |
21.99 |
| 2026-02-19 12:00 |
12:15:33.16 |
-60:03:19.0 |
HIP 59546 |
21.24 |
| 2026-02-20 00:00 |
12:15:27.04 |
-60:03:34.7 |
HIP 59546 |
20.49 |
| 2026-02-20 12:00 |
12:15:20.88 |
-60:03:49.9 |
HIP 59546 |
19.74 |
| 2026-02-21 00:00 |
12:15:14.67 |
-60:04:04.6 |
HIP 59546 |
18.99 |
| 2026-02-21 12:00 |
12:15:08.43 |
-60:04:18.9 |
HIP 59546 |
18.23 |
| 2026-02-22 00:00 |
12:15:02.15 |
-60:04:32.6 |
HIP 59546 |
17.48 |
| 2026-02-22 12:00 |
12:14:55.84 |
-60:04:45.8 |
HIP 59546 |
16.72 |
| 2026-02-23 00:00 |
12:14:49.48 |
-60:04:58.6 |
HIP 59546 |
15.97 |
| 2026-02-23 12:00 |
12:14:43.09 |
-60:05:10.9 |
HIP 59546 |
15.22 |
| 2026-02-24 00:00 |
12:14:36.66 |
-60:05:22.6 |
HIP 59546 |
14.47 |